The interesting thing for this specific promotion is that there were many spelling and grammar mistakes, both in the offer itself and in the t&c's:

flexibel and flexibe, Oktober, Dezember, "collecting according to the brand", "an booking [...] date",

as if this was a promotion created by a local German team without being reviewed (nor approved?) by corporate.

That may (or may not) be the reason why it has now been revoked? Who knows....